Interlock between switch and cable connector for electrical apparatus



July 22, 1969 w. A. M MORRIS 3,457,381 INTERLOCK BETWEEN SWITCH ANDCABLE CONNECTOR FOR ELECTRICAL APPARATUS Filed March 21, 1967 UnitedStates Patent US. Cl. 200-50 2 Claims ABSTRACT OF THE DISCLOSURE Aninterlock between a switch and cable connector to prevent removal of thecable connector when the switch is in closed position. A switch handleis located on the exterior of an electrical apparatus and the cableconnector is similarly mounted near the switch handle. The cableconnector is provided with a clamping device which rotates between anunlocked position to a locked position in which it engages a pair oflugs on the exterior of the electrical apparatus. When the clampingdevice is in its locked position, the switch handle will be ininterference contact with the clamping device when the switch is closed,preventing movement of the clamping device to the unlocked position.

Background of invention This invention relates to interlocks and moreparticularly, to an interlock between a switch and a cable connector foruse in electrical apparatus.

There is presently a well-defined, growing trend in electricaldistribution from overhead, open wire electrical distribution tounderground, buried wire distribution. With this growing trend, manyutilities are evolving new operating procedures to develop safe,efiicient operating practices for underground servicing. At the sametime, equipment manufacturers are attempting to build distributionequipment which may be used with these new operating procedures. Manytypes of distribution apparatus are now provided with plug-in cableconnectors which may be removed by the lineman when servicing theequipment. The removal of the connector provides a positive, visuallyverifiable opening of the circuit to or from the electrical apparatus.While many of these connectors are provided with design capabiilty ofinterrupting current when unplugged or disconnected, many utilitiesprefer, for safety reasons, to electrically open the cir cuit before theconnector is removed. To provide this desirable open circuit feature,many types of electrical apparatus using plug-in cable connectors arealso provided with switching means to open the circuit from theapparatus to the cable before the cable connector is removed. In orderto be sure that the switch is in open circuit position beforedisconnecting the cable, it is believed desirable to provide aninterlock between such cable and connector.

It is therefore, one object of this invention to provide a novelinterlock between a cable connector and a switch of an electricalapparatus to prevent removal of the cable while the switch is in theclosed position.

A further object of this invention is to provide a novel interlock usingthe cable connector locking device in conjunction with the switchhandle.

Summary of invention Briefly, in one form, the interlock of thisinvention comprises a cable connector removably mounted on an electricalapparatus and having a rotatable clamping ring for locking the cableconnector to a pair of lugs on the electrical apparatus, when theclamping ring is rotated to a locked position. A switch operating memberis also mounted on the electrical apparatus and movable between a switchopened and a switch closed position. When the switch operating member isin the switch closed position, it has a portion in interference contactwith the clamping ring when the clamping ring is in locked positionpreventing rotation of the clamping ring.

The invention which is sought to be protected will be particularlypointed out and distinctly claimed in the claims appended hereto.However, it is believed that this invention and the manner in which itsvarious objects and advantages are obtained, as well as other objectsand advantages thereof, will be better understood from the followingdetailed description of a preferred embodiment thereof, particularlywhen considered in the light of the accompanying drawing.

Brief description of drawing FIGURE 1 is a perspective view of one formof interlock between a cable connector and a switch according to thisinvention;

FIGURE 2 is a top view of a modified form of interlock, similar to thatshown in FIGURE 1, partially in section and with parts eliminated tomore clearly show the operation of the interlock;

FIGURE 3 is an exploded view of the portion of the interlock relating tothe cable connector;

FIGURE 4 is a detailed sectional view of one portion of the interlock ofthe cable connector; and

FIGURE 5 is a side view of one of the locking lugs showing a preferredform thereof.

escription of preferred embodiment This invention relates to aninterlocking means between a switch and a cable connector in which theswitch operating mechanism is in interfering relation with the clampingdevice of the cable connector, when the switch is in closed position.The preferred embodiment set forth herein discloses the present specificconstruction believed most suitable for obtaining its various objectsand advantages. Obviously, changes may be made in various structuraldetails without departing from the scope of the defined invention.

Referring now to the drawing in which like numerals are used to indicatelike parts throughout and referring particularly to FIGURE 1, thepreferred form of interlock of this invention is shown as applied to anL-shaped cable connector 10 which is connected to a stud or bushingmember (not shown) mounted on a wall portion or cover 12 or anelectrical apparatus, such as, for example a distribution transformer.As will be understood, the stud or bushing (not shown) is connected tothe electrical element of the apparatus and receives electrical powerfrom the cable connector 10. Cable connector 10 is provided with aflanged member 14 on the lower part thereof as shown. The flange member14 is secured to cable connector 10 by a bail 16. Rotatably mounted onflange member 14 is a ring member 18 which is the clamping ring tosecure cable connector 10 to the stud of the electrical apparatus.

As can be seen from FIGURE 1, clamping ring 18 rides on the flange 20 offlange member 14 and engages a pair of lugs 22, 24 when in the clampedor locked position shown. A handle portion 26 is provided on theclamping ring 18 having an opening 28 to enable operation of theclamping ring 18 by means of a hook stick or the like, as will bereadily understood. The handle portion 26 also locks or clamps under thelug 24 as shown. In a similar manner, the opposite side of clamping ring18 has a locking portion 30 which hooks or clamps under the lug 22. Thusclamping ring 18 may be rotated on flange 20 of-the flange member 14 tolock or clamp the cable connector in the position as is shown. Bail 16is also provided with an opening 32 to enable the cable connector 10 tobe placed on or removed from the bushing (not shown) on wall portion orcover member 12 of the electrical apparatus. As will be understood, ahook stick or similar tool may engage bail 16 through opening 32 toenable cable connector 10 to be removed from or placed on the stud orbushing of the electrical apparatus.

The relationship of flange member 14, bail 16 and clamping ring 18 arebest shown in the exploded perspective view of FIGURE 3. As is shown,flange member 14 has a flange 20 and slots 34, only one of which isshown, on the opposite sides thereof. The ball member 16 has hookedportions 36 which hook into the slots 34, in the manner best shown inFIGURE 4. Bail 16 is also provided with a slide member 38 whichcooperates with a raised portion 40 on cable connector 10 to secure bail16 to cable connector 10, as is best shown in FIGURE 1. It will ofcourse, be apparent that the slide member 38 could be readily fastenedby rivets or other means to the portion 40 of cable connector 10 ifdesired. Further, it will be understood that flange member 14 maycontact raised members, such as member 42 on the lower portion of thecable connector 10, or it may be of sufficient length to meet theenlarged portion 44 of cable connector 10. As will be understood, bailmember 16 securely holds the flange member 14 on the lower portion ofthe cable connector 10 such that the clamping ring 18 may lock the cableconnector 10 to the wall portion or cover member 12 of the electricalapparatus. However, to enable the opening 32 of bail member 16 to beused to remove the cable connector from the wall portion or cover 12 ofthe electrical apparatus it is necessary that the flange member 14 bemounted such that it cannot ride up to any extent on the lower portionof cable connector 10.

The log members 22 and 24 are mounted on the wall or cover 12 of theelectrical apparatus in any desired manner, a weldment being shown at 46in FIGURE 1. In the preferred form, the lugs 22 and 24 are L-shaped withone portion of the L being welded or otherwise secured to the wallportion or cover member 12, as is shown. The preferred shape of lugmembers 22 and 24 is best shown in FIGURE 5. As can be seen from FIGURE5, the open end of the L-shaped lug member 24 is provided with a taperedportion 48 which tapers toward the open portion of the lug member. Aswill be understood, as the clamping ring 18 is turned under lug members22 and 24, the handle 26 and the locking extension will contact thetapered portion 48 and slide the handle 26 and locking portion 30 downunder the open portion of lugs 22 and 24, thus securely tightening thecable connector 10 to the stud or bushing (not shown) which is mountedon the wall member or cover 12.

Also provided on wall member or cover 12 is a switch handle 50 which isprovided with an opening 52 which may be used with a hook stick or thelike for opening and closing the switch member 50. As will beunderstood, the switch member 50 is the operating member or handle for aswitch which is located within the electrical apparatus below the wallportion or cover member 12. Operation of the switch member 50 will openor close the switch within the electrical apparatus in a manner which iswell understood by those skilled in the art. This opening and closing asmentioned can be performed by a hook stick or the like which is hookedinto the opening 52 of the switch member 50.

FIGURE 1 shows one form of switch handle 50 which may be used with theinterlock of this invention, while FIGURE 2 shows a modified form ofswitch handle 50; equally useful in this invention.

As is shown in FIGURE 1, switch member 50 is movably mounted on Wallportion or cover member 12 in the vicinity of the cable connector 10. Aswill be obvious, the switch member 50 movable between an open and aclosed position. In the open position, as shown in FIG- URE l, theswitch member 50 does not interfere with the clamping ring 18, such thatthe clamping ring may be readily rotated about flange 20 of flangemember 14 to unclamp or unlock the cable connector 10 from the lugs 22,24 on the wall portion or cover member 12. However, when the switchmember 50 is moved to its closed position, as will be apparent, anextended portion 54 having a locking notch 56 will move into interferingcontact or position with the locking portion 30 of clamping ring 18.This portion is best shown in the modified form of interlock shown inFIGURE 2 of the drawing.

Referring now to FIGURE 2, which is a top view of the interlock with aportion of the flange member 14 in section, and the cable connector 10eliminated, it can be seen that with the clamping ring 18 in lockedposition under lugs 22 and 24, that the locking portion 3 0 of theclamping ring 18 is in interfering position with portion 56' of switchmember 50 when the switch member is in the closed position as is shownin FIGURE 2. Of course, it will be apparent to those skilled in the art,that the switch member 50 may be provided with the extension 56' whichwill provide interference contact with the locking portion 30 ofclamping member 18. However, if desired, the notched portion 56, shownin FIGURE 1, may be provided on the extending portion 54 of switchmember 50. Notch 56 may make contact with the extended locking portion30 of clamping ring 18 thereby allowing the top part 54 of the extensionof handle 50 to cover the remainder of the locking member 30. Obviously,in either case, the notch 56 or portion 56' will provide an interferencecontact with the locking portion 30 of clamping ring 18, preventing theclamping ring from being moved to an unlocked position when the switchmember 50 or 50" is in the closed position. As switch member 50 or 50 ismoved to the open position, which is best shown in FIG- URE 1, theinterference contact is removed, thereby a1- lowing clamping member 18to be rotated to be disengaged from the lugs 22, 24 to allow removal ofthe connector 10. When a locking notch 56 is used, as in FIG- URE 1, itmay be desirable to provide a cut-out portion tion 58 to preventinterference between handle 50 and locking portion 30 When the handle 50is rotated to open position.

While there have been shown and described the present preferredembodiment of the invention, it will be apparent to those skilled in theart that various changes may be made in constructional details withoutdeparting from the spirit and scope of the invention, particularly as itis defined in the appended claims.

What is claimed as new and which it is desired to secure by LettersPatent of the United States is:

1. An interlock between a switch and cable connector for an electricalapparatus comprising:

(a) a fixed portion of the electrical apparatus,

(b) a movable switch handle mounted on the exterior of said fixedportion,

(0) a removable cable connector mounted on the exterior of said fixedportion in the vicinity of said switch handle,

(1) a flange member secured to said cable connector,

(2) a clamping ring rotatably mounted on the flange of said flangemember,

(3) a bail member connected to said cable connector and to said flangemember for securing said flange member to said cable connector,

(d) a pair of upstanding locking lugs secured to said fixed portion inlocking position with respect to said clamping ring whereby when saidclamping ring is in a first position, it is free of said lugs and whenrotated to a second position, said clamping ring locks with said lugs,

and said switch handle movable to two positions, said switch handle whenin a first position preventing said clamping ring from moving from saidsecond to said first position and when said switch handle is in a secondposition, allowing said clamping ring to move from said second to saidfirst position.

2. An interlock between a switch and cable connector for an electricalapparatus comprising:

(a) a fixed portion of the electrical apparatus,

(b) a movable switch handle mounted on the exterior of said fixedportion,

(c) a removable cable connector mounted on the exterior of said fixedportion in the vicinity of said switch handle,

(1) a flange member secured to said cable connector,

(2) a clamping ring rotatably mounted on the flange of said flangemember,

(d) a pair of upstanding locking lugs secured to said fixed portion inlocking position with respect to said clamping ring whereby when saidclamping ring is in a first position, it is free of said lugs and whenrotated to a second position, said clamping ring locks with said lugs,

and said switch handle movable to two positions, said switch handle whenin a first position preventing said clamping ring from moving from saidsecond to said first position and when said switch handle is in a secondposition, allowing said clamping ring to move from said second to saidfirst position, and said clamping ring having a portion extending beyondsaid locking lugs, said extending portion being in interfering relationwith said switch handle when said clamping ring is in said secondposition and said switch handle is in said first position.

References Cited UNITED STATES PATENTS 2,397,595 4/1946 Conlan ZOO-50.2

ROBERT K. SCI-IAEFER, Primary Examiner ROBERT A. VANDERHYE, AssistantExaminer US. Cl. X.R. 200-51

